Safety Investigation of Millimeter Wave Radar to Monitor Vital Signs in the NICU

Abstract

Neonates are among the most fragile in the human population. Even more so when born prematurely. Their loss of development time in the womb disrupts their growth, and the neonatal intensive care unit environment can add multiple stresses that hinder their development. This can partly be attributed to the intrusive environment of a neonatal intensive care unit incubator. Neonatal development cannot be monitored without multiple wires and sensors, such as pulse oximetry and electrocardiogram (ECG). The strong adhesives of these sensors can hurt the delicate skin of the neonates and the sensors make bonding with parents difficult. The issue of the intrusive nature of current neonatal healthcare has led this thesis towards something not normally associated with healthcare: radar. Millimeter wave radar with frequency modulation of the continuous wave transmission has been shown to measure adult’s heart and respiration rate without contact with the patient. Using the small wavelength and high configurability of frequency modulated millimeter wave radar, the goal will be to scale down this technology from adults to neonates that can be as small as 500 grams. This thesis provides a look into the application investigation of frequency modulated millimeter wave radar in monitoring neonates. It dives into the environment of the neonatal intensive care unit incubator and the radar monitoring system operation. The environment is modelled with a thermal focus to avoid high temperature increases caused by the radar module. The system operation is described and the most influential component simulated and characterized. Lastly, the thermal model of the neonatal intensive care unit incubator is validated to understand how the system operation influences the environment. And the radar system operation will be characterized for measuring the smallest amplitude changes of a chest to understand how the environment influences the system performance. The conclusion of this thesis will provide reasoning for why or why not the application of frequency modulated millimeter wave radar has the capability to be safely implemented in the neonatal intensive care unit.